Glycolysis :

1. Glycolysis: • Each slide in this presentation represents one step in the reordering exercise. The order of the slides can be used to verify that your sequence is in the correct order.

2. Two ATP are consumed, forming 2 ADP + 2 Pi. glucose (C6) 2 ATP 2 ADP Two ATP are consumed during glycolysis. P-C6-P This results in a 6-carbon compound that has 2 phosphate groups. 2C3 2 pyruvate (C3)

3. Two 3-carbon compounds are produced. glucose (C6) 2 ATP 2 ADP Several different 3-carbon compounds are produced during the reactions. The designation “C3” is used here to represent all of them. Be aware that in addition to carbon, these compounds also contain oxygen and hydrogen. 2C3 2 pyruvate (C3)

4. Two NADH are produced from 2 NAD+. glucose (C6) 2 ATP 2 ADP P-C6-P 2 C3-P 2 NAD+ NAD+ picks up two electrons to become NADH. 2 NADH The goal of cellular respiration is to produce ATP. NADH contains energy that can be used to produce ATP. This will be discussed later. 2 pyruvate (C3)

5. Four ATP are produced by substrate-level phosphorylation. glucose (C6) 2 ATP 2 ADP P-C6-P 2 C3-P 2 NAD+ 2 NADH 2 P-C3-P 2 ADP 2 ATP Four ATP are produced by substrate-level phosphorylation. 2 ADP 2 ATP 2 pyruvate (C3)

6. Two molecules of pyruvate are formed from each glucose molecule. glucose (C6) 4 ATP produced - 2 ATP consumed 2 ATP net 2 NADH are also produced 2 ATP 2 ADP Glycolysis does not require oxygen (it is anaerobic). It occurs in the cytoplasm. P-C6-P 2 C3-P 2 NAD+ 2 NADH 2 P-C3-P 2 ADP 2 ATP 2 ADP 2 ATP 2 pyruvate (C3)

7. Formation of Acetyl CoA:

8. A carbon atom is removed from each of the pyruvate molecules forming a two-carbon compound and CO2. 2 Coenzyme A 2 CO2 2 pyruvate (C3) 2 acetyl CoA (C2-CoA) 2 NAD+ 2 NADH

9. Each of the two-carbon compounds is oxidized forming NADH from NAD+. 2 Coenzyme A 2 CO2 2 pyruvate (C3) 2 acetyl CoA (C2-CoA) 2 NAD+ 2 NADH

10. Coenzyme A is attached to each of the two-carbon compounds producing two acetyl CoA molecules. 2 Coenzyme A 2 CO2 2 pyruvate (C3) 2 acetyl CoA (C2-CoA) 2 NAD+ 2 NADH

11. Citric Acid (Kreb’s) Cycle:

12. Coenzyme A is removed when the two-carbon compound is attached to a four-carbon compound producing a six-carbon compound (citrate). C2 (acetyl CoA) Coenzyme A C6 C4 Acetyl CoA + C4 C6 + Coenzyme A

13. Each citrate molecule undergoes a series of reactions that removes 2 carbon atoms which are released as CO2. In addition, 3 NADH, 1 ATP, and 1 FADH2 are produced. The four-carbon compound that began the cycle is regenerated. C2 (acetyl CoA) Coenzyme A C6 NADH CO2 C4 C5 NADH CO2 ATP FADH2 NADH

14. Electron Transport System and Chemiosmotic Phosphorylation:

15. NADH and FADH2 carry electrons to proton pumps embedded in the inner membrane of the mitochondrion. H+ H+ H+ H+ H+ H+ NADH H+ H+ H+ H+ H+ H+ H+ H+

16. Energy from NADH and FADH2 is used to pump H+ into the intermembrane space. H+ H+ H+ 2H+ + 2e- + 1/2 O2 H2O NADH H+ H+ H+ H+ H+ H+ H+ H+ H+ H+

17. Hydrogen ions force their way through ATP synthase due to their higher concentration in the intermembrane space. H+ H+ H+ 2H+ + 2e- + 1/2 O2 H2O NADH H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+

18. ATP synthase uses energy from the H+ concentration to phosphorylate ADP. H+ H+ H+ 2H+ + 2e- + 1/2 O2 H2O NADH H+ H+ H+ H+ H+ H+ ADP + Pi ATP H+ H+ H+ H+ H+

19. glucose (C6) Summary Glycolysis 2 ATP 2 ADP Citric Acid Cycle 2 C3 2 NAD+ 2 ADP Formation of Acetyl CoA 2 NADH 2 ATP 2 C2 (acetyl CoA) 2 ADP 2 C6 2 CO2 2 NADH 2 ATP 2 acetyl groups (C2) 2 pyruvate (C3) 2 CO2 2 C5 2 C4 2 NAD+ 2 NADH 2 NADH 2 CO2 2 ATP 2 NADH 2 FADH2 10 NAD+ 2 FAD electron transport 1/2 O2 32-34 ATP H2O